Closures also known as caps and lids are used with a wide variety of containers. The closures vary greatly with respect to geometry and the materials of which they are manufactured. One well known closure is used as a temporary cover for beverage containers associated with the fast food industry. The beverages, either hot or cold, are dispensed into a paper or plastic cup and then transported for a short distance before the beverage is consumed. The closures used with hand held beverages are generally thermoformed of relatively thin flexible plastic material, such as for example, polystyrene or polyethylene.
Since the beverage containers are fragile in nature, they cannot withstand direct axial loading of any great magnitude. Consequently, the closure structure, including the lip thereof, is quite flexible, thus facilitating installation of the closure over and around the container bead. The closures have incorporated into the peripheral lip a locking mechanism that snaps into engagement with the container rim.
The closures manufactured for hot and cold beverage cups are extremely light in weight and have a tendency to stick together when stacked. To prevent the nested closures from sticking together when assembled in a stack, the top of the closure is modified from its generally planar configuration and includes indentations strategically positioned to prevent tight nesting. In many instances the denesting features are so pronounced so as to permit one closure to slide freely over the top of another without any interference from the downwardly protruding rim.
Thus it becomes apparent that if the closures are designed so that they do not nest, there will be little if any lateral stability when the closures are stacked one upon another. Various racks have been designed to accommodate and make available closures in areas where soft drinks, coffee and other beverages are sold. The existing racks necessitate removal of the closures by grasping the closure with the fingers. Invariably more than one closure is touched in the process of removing the desired closure.